Hi there,
First of all, congrats, this is a great script., and can fit almost 100% in my needs. Though, I am a bit confused with the classibase themes:

a) If you purchase classibase, you have access to all the themes/templates (i.e., Mukusic, Odsnocvet, Minimalist, etc.)
b) can I use the script for multiple sites (domains)
c) The theme Minimalits, is from OSCLASS which is another script marketed by another company (osclass.org) .. or you are a kind of partners..?. and osclass is a free to use classified script. A bit confused here.

I am very interested to purchase the script.. I may have more questions that I will post later, all of them pre-sales type of questions.

a) If you purchase classibase, you have access to all the themes/templates (i.e., Mukusic, Odsnocvet, Minimalist, etc.)
Yes, you will have access to all those themes and to future themes for time depending on your purchase. if you purchase yearly plan then you will have access for one year, if forever plan then you will have access forever.

b) can I use the script for multiple sites (domains)
Yes, you can use script for multiple domains.

c) The theme Minimalits, is from OSCLASS which is another script marketed by another company (osclass.org) .. or you are a kind of partners..?. and osclass is a free to use classified script. A bit confused here.
We are not partners with osclass. We plan to release premium osclass themes in future. Minimalist for osclass is free theme built to measure market interest. Future osclass themes will be paid and will look like existing Classibase themes. We did not start any work for those themes yet and there is no set date for them.

I have gone through the demo (user & admin), and my conclusion is that the app is perfect for me to use it as a classified or even directory site. I do appreciate if you can give some more information before I purchase regarding: (my apologize for the long list.. 🙂

a) Can we create additional email templates.
b) Can we import ads (full), from a CSV file.
c) Can we change Header/Background color/dimensions easily.
d) Can we put different ads depending on the category selected by the user.
f) Can we put a regional map in the homepage.
g) Is French, Dutch and Portuguese languages available. In the plan..?
h) Can breadcrumbs and menu items be added to ease navigation.
i) Can I purchase the app and install it in my local host temporarly, so then after customizing and testing, move it to a web host.
j) Can Category titles in the homepage be customized to include an icon and different colors/size/fonts.?
k) Does it require WP to run..?. If not, how the script works..?
l) Loading speed compared with a site powered by Joomla or WP..?
m) I plan to have approx. 15,000 listings.. Can it be handled by the script.
n) I expect within one year to have 2,000 users/day, and apprx. 10,000 pageviews/day.. what do you recommend regarding web hosting..?
o) Do you accept Visa or Master card for the purchase.?

a) Can we create additional email templates.
No, you can edit existing templates. if you create new template how you want to send it? or you want make special template for ex. Christmas period only?

b) Can we import ads (full), from a CSV file.
No, but there is xml import in “Tools” -> “Import data” page. you can create xml from csv using PHP, if you know how. Only admin has access to this feature. If it is vital for you we can will consider adding it to our next update, it will work exacly as xml but will accept CSV as well. Let us know your in case you want it.

c) Can we change Header/Background color/dimensions easily.
Site header and visual properties yes for front end, some themes has built in color picker for changing color and logo, background uploader. on admin pages you cannot change, only if you know CSS you can add custom CSS to all pages from admin panel.

d) Can we put different ads depending on the category selected by the user.
Can you clarify? if you want to have different custom fields for different categories then yes.

f) Can we put a regional map in the homepage.
If it is some HTML/javascript then you can use text widget to put any HTML/javascript/PHP code. You will have to find map code and put it there with links to locations. for example using sites like this http://createaclickablemap.com/

g) Is French, Dutch and Portuguese languages available. In the plan..?
No not available and not planned, but if you know those languages then you can use built in tranlation button which uses microsoft tanslation service and then fix some errors. it is in “Settings” -> “Languages” add new language and then click on “TranslateT button next to it. new page will open, there will be “Auto translate empty fields” button. Also use “Display empty values” button to see terms that need translation.

h) Can breadcrumbs and menu items be added to ease navigation.
Breadcrumb is already added in all themes. you cannot customize it. There is one Mukuzik theme with drop down menu, others have categories and locations on sidebar. you can code custom menu in HTML using text widget if you want.

i) Can I purchase the app and install it in my local host temporarly, so then after customizing and testing, move it to a web host.
Yes.

j) Can Category titles in the homepage be customized to include an icon and different colors/size/fonts.?
No.

k) Does it require WP to run..?. If not, how the script works..?
No, it is stand alone PHP script. System requrements are listed on classibase.com home page at the bottom.

l) Loading speed compared with a site powered by Joomla or WP..?
It is faster than WP and Jooml. We load only required classes for each page. mempry usage is on avarage 5 MB, where WP is 20MB without plugins I think.

m) I plan to have approx. 15,000 listings.. Can it be handled by the script.
Yes, we tested it with 100,000 ads on our localhost, works normal. We cache some slow queries like counting number of ads.

n) I expect within one year to have 2,000 users/day, and apprx. 10,000 pageviews/day.. what do you recommend regarding web hosting..?
Dedicated server with 1.2 Ghz CPU and 1GB RAM should be fine for it. You can start with shared serve and move to dedicated later.

o) Do you accept Visa or Master card for the purchase.?
No, paypal does accept them. you should be able to pay without registration I guess.